il-33trap

IL-33trap is a novel recombinant fusion protein designed as a high-affinity antagonist of IL-33, a key cytokine implicated in allergic and inflammatory diseases such as asthma and atopic dermatitis. The drug combines the extracellular domains of the IL-33 receptor (ST2) and its co-receptor (IL-1 receptor accessory protein, IL-1RAcP), linked by a flexible glycine-glycine-serine (GGS) linker[1][3]. This design mimics the natural signaling complex, enabling IL-33trap to bind IL-33 with much higher affinity than the endogenous decoy receptor, soluble ST2 (sST2)[1][3]. In preclinical studies, IL-33trap has demonstrated potent inhibition of IL-33 signaling in vitro and in vivo, effectively blocking eosinophil infiltration, cytokine production, and airway inflammation in mouse models of allergic asthma[1][3]. IL-33trap is produced as a recombinant protein in human cell lines and is glycosylated, similar to the natural receptors[1]. It specifically targets only bioactive IL-33 isoforms, avoiding neutralization by inactive splice variants, which may confer an advantage over some monoclonal antibodies[3]. Development has focused on preclinical models, with promising anti-inflammatory effects, but no clinical trials or approvals in humans have been reported yet.